What physical and chemical properties of elements were used by Mendeleev in creating his Periodic Table? List two observations which posed a challenge to Mendeleev’s Periodic Law.

Question

Philoid · Accepted Answer

“The physical and chemical properties of the elements are the periodic functions of their atomic weights”.

According to Mendeleev periodic law, the characteristic property of the elements is based on their atomic weights. In this periodic table, elements are arranged in increasing order of their atomic weight.

Two observations which posed a challenge to Mendeleev’s periodic Law are:

•Isotopes of all elements posed a challenge to Mendeleev’s periodic law.

•The atomic masses do not increase in a regular manner in going from element to another so, it was not possible to predict how many elements could be discovered between 2 elements.